JAMB - Physics (1989 - No. 16)
Light of wavelength 5000 x 10-8cm travels in free space with a velocity of 3 x 108ms-1. What is its wavelength in glass of refractive index 1.5?
3333 x 10-8cm
5000 x 10-8cm
6666 x10-8cm
750010-8cm
Wyjaśnienie
n = \(\frac{\text{wavelength in space}}{\text{wavelength in glass}}\)
1.5 = \(\frac{5000 \times 10^{-8}}{\lambda g}\)
\(\lambda\)g = 3333 x 10-8cm
1.5 = \(\frac{5000 \times 10^{-8}}{\lambda g}\)
\(\lambda\)g = 3333 x 10-8cm